We had a running
light cover break on our 2011
Casita. The guys at the RV shop said, everyone uses the same style, it's called "Winnebago". They didn't sell the lens itself, you had to buy the entire unit. Which wasn't expensive, really.
In our case, we used 12v bulbs. If I were to do it again, I'd use LEDs, but I don't know if that requires rewiring it?
If so, I'm the wrong person to ask, I'm a field biologist, not an electrician. And quite honestly, the amount of juice it takes to run the 12v
light bulb for the relatively short amount of time you have the running
lights on, I doubt there's much in difference in the amount of electricity used in either one.